Wrist pin lock



March 27, 1934. J. FLAMMANG ET AL WRIST PIN LOCK Filed Oct. 13, 1932 mix 40 ticularly to Figures 3 and 4, 1 designates a wrist plane as the body portion of the locking piece 4.

Patented Mar. 27, 1934 1,952,202 wms'r PIN LOCK John Flammang, University City, Percy L. Bowser, St. Louis, and Herman Ernst, Pine Lawn, Mo., assignors to The Stirling Corporation, St. Louis, Mo., a corporation of Delaware Application October 13, 1932, Serial No. 637,580

11 Claims. (01. 30919) This invention pertains to locking devices, and ing piece 4 is provided with an extension or stem more particularly to means for locking a wrist 6 adapted to extend to the opposite side of the bore pin in a piston so as to secure the same against 2 of the wrist pin. The length of the stem 6 is end play. so adjusted that when the locking piece is in nor- One of the objects of this invention is to provide mal position in the socket or slot 3 with the end 60 a locking device of simplified structure which will of the stem 6 engaging the wall of the bore.2, retain the wrist pin in place and which may easily the rim 5 will protrude slightly beyond the outer be manipulated so as to release the pin for reperiphery of the wrist pin. The locking piece 4 moval. is preferably constructed of relatively soft or V V Another object is to provide a device of this bendable material so that the stem 6 may be bent 66 kind which will take up the minimum of space. laterally as indicated in dotted l nes in Figure 3.

Another object is to provide such a device which When so deflected its radial dimension is reduced will interfere to a minimum extent with the bearso as to permit the locking piece to be retracted ing of the wrist pin in the piston boss, or in the in the socket 3 so as to bring the rim 5 within the connecting rod. outer periphery of the wrist pin. A recess or 70 Another object is to provide such a device perforation or other suitable element 7 may. be

which when locked will be perfectly secured provided on the locking piece 4 for the engage against accidental unlocking. ment of an implement to assist in retracting the Further objects will appear from the followlocking piece when desired. ing description taken in connection with the fol- Referring now to Figure 1 the piston 8 to which 76 lowing drawing, in which: the wrist pin 1 is to be applied is'provided with an Figure 1 is a sectionalview showing a wrist annular groove 9 0n the in ri f h Wrist D n pin in the piston boss and the manner of applibearing. This groove is suitably located to match cation of the locking device in'accordance with the location of a socket 3 in the wrist pin so that this invention; when these recesses are brought into registry 80 Figure 2 is a similar view showing the device with each other the wrist pin will be properly 10- applied to lock the wrist pin in the connecting cated in the piston with its ends clear of the cylrod; inder wall. The locking piece 4 is first inserted Figure 3 is a side View of a hollow wrist pin in the wrist pin with the stem 6 bent laterally so showing a locking device applied in accordance as to permit retraction of the locking piece as dewith this invention; scribed. With the locking piece in retracted po- Figure 4 is a section on line 4-4 of Figure 3; sition the pin is inserted in the wrist pin bearings Figures 5 and 6 are views similarto Figures 3 and moved so as to bring the socket 3 into regisand 4 respectively illustrating another .emboditry with the annular groove 9 in the D 10058. ment of this invention; and When such registry has been effected the locking 90 Figure 7 is a sectional view similar to Figure piece 4 is moved outwardly so that the rimportion 6 illustrating I still another embodiment of this 5 will enter the groove 9. A suitable tool may now invention. be inserted through the bore 2 so as to straighten Referring now to the drawing and more parthe stem 6 to its normal position in the same pin of the ordinary type. This pin may be pro- This not only forces the locking piece into the vided with a bore 2 as is customary for such pins groove 9 but the stem 6 maintains it in this poare usually made hollow. The pin 1 is provided sition so that the wrist pin is permanently locked at a suitable point along its length with a transin the piston. verse slot 3 extending almost to its center. This In Figure 2 a similar construction is illustrated 1 slot provides a guide socket for a locking piece 4. except that the groove 9 is formed in the bearing The piece 4 is preferably flat and may be formed, of the connecting rod instead of in the wrist pin for instance, by punching from sheet metal of boss. In this case the wrist pin is locked in the suitable thickness or other suitable material. connecting rod instead of in the piston. In The body portion of the locking piece 4 is genereither case it is locked against endwise movement 105 ally semi-circular in form and may be provided and can not, therefore, come into contact with with a rim 5 of a radius slightly larger than that the cylinder wall.

of the pin 1 and adapted to protrude outside of In the embodiments of Figures 5 and 6 the the pin when in looking position. stem 6 is made somewhat shorter than in Fig- In the embodiments of Figures 3 and 4 the lockures 3 and 4 and has mounted thereon a suitable H0 compression spring 10 tending to force the looking piece outwardly. This device is applied to the piston by inserting a pin with the locking piece retracted against the pressure of the spring 10 and held retracted until the same passes into the wrist pin bearing. If the pin is then moved so as to bring the socket 3 into registry with the groove 9 the locking piece will snap into said groove in response to the pressure of the spring 10. In Figure '7 instead of a pronounced stem the locking piece 4 is provided with a downward projection 11 adapted to engage a spring 12 of the flat leaf type whose ends are arranged to rest on the bottom of the groove 3. The spring 12 also urges the locking piece outwardly so as to cause it to snap into the groove 9 as already explained.

It will be seen that this invention provides a locking device of very simple design and of a minimum cost. It is not only certain in its action, but it takes up very little room so that the amount of the wrist pin bearing surface which is sacrificed to provide such a locking feature is reduced to a minimum. The pin is not only locked in the piston, but may easily and quickly be removed therefrom. In the embodiment of Figures 3 and 4 it is only necessary to bend the stem 6 to one side and then insert a suitable implement in the recess '7 to retract the locking piece and remove the pin. The other embodiments are similarly manipulated.

While this invention has been described as including the locking piece, the wrist pin and the piston on a unitary structure, it will be understood, of course, that individual features and subcombinations may be useful without reference to the rest of the general combination. It is understood, therefore, that the employment of such individual features and sub-combinations is contemplated by this invention and within the scope of the appended claims.

It is further obvious that various changes may be made, within the scope of the appended claims, in the details of construction without departing from the spirit of this invention; it is to be understood, therfore, that this invention is not limited to the specific details shown and described.

Having thus described the invention, what is claimed is:

l. In combination with a wrist pin having a socket, a lock whose body is adapted for perma nent deformation to extend and contract the same in said socket, said lock having a locking portion projectable beyond said socket when the body is extended.

2. In combination with a wrist pin having a socket, a lock having a body adapted for non-resilient extension and contraction in said socket,

means for maintaining said body in extended position, and means for retracting said body.

3. In combination with a hollow wrist pin having a relatively narrow transverse slot providing a socket, a locking piece having a relatively thin fiat body adapted to be guided in said socket and an arcuate rim, and means for maintaining said body in extended position in said socket with its rim protruding from the socket.

4. In combination with a hollow wrist pin having a transverse slot providing a socket, a locking piece having a flat body adapted to be guided in said socket, and a non-resilient bendable extension on said body adapted when bent to permit retraction of said body and when straightened to support said body in looking position.

5. In combination with a hollow wrist pin having a transverse slot providing a socket, a locking piece having a flat body adapted to be guided in said socket, and a non-resilient bendable stem extending inwardly of the pin adapted when bent to permit retraction of said body and when straightened to engage the inner wall of the pin to maintain said body in locking position.

6. In combination with a wrist pin having a socket, a locking piece carried by said pin and guided in said socket and having non-resilient means adapted for manipulation to contract and extend said locking piece.

'7. In combination with a wrist pin having a socket and a bearing therefor having a socket in alinement with said pin socket, a non-resilient locking piece engageable with said alined sockets to lock said pin in its bearing, said locking piece being dimensioned to engage said bearing socket when in unbent condition and being bendable to reduce its extent in order to disengage the bearing socket.

8. In combination with a hollow wrist pin having a transverse slot providing a socket, a locking piece comprising a flat plate guided in said socket and having an arcuate rim positioned to protrude beyond and extend around the circumference of the pin when in extended position, and means for contracting and extending said locking piece.

9. A pin lock, comprising, a flat plate having an arcuate circumferential locking edge, and means for extending and contracting said plate.

10. In combination with a wrist pin having a socket, a non-resilient deformable locking piece guided in said socket.

11. In combination with a wrist pin having a transverse slot providing a socket, a fiat plate having an arcuate circumferential locking edge guided in said socket.

JOHN FLAMMANG. PERCY L. BOWSER. HERMAN ERNST. 

